Strictly speaking, there was no need to keep confirming call signs on a two-man follow, but Jim had insisted upon it to get her into the habit. At this rate, she’d have it down by around this time next year.

‘Delta Seven, yes yes. Making ground. I can take eyeball when he turns.’

Looking conspicuously unlike a cop or an ex-cop, and bearing no resemblance whatsoever to a private investigator (particularly in the way she practised her new-found profession of private investigation), it had been Jasmine’s job on Monday to hit the front doors.

It had happened at the second address. The first address was a dud: the ex-girlfriend who was meant to be living there had sold up two years back. Jim had had his doubts about it in any case, but they’d given it a shot as it was en route to the place on which they had the soundest intel. Technically, the second address was actually addresses two through ten, as it was a three-storey tenement in Partick and they only had the number of the building, not the flat.

‘Foxtrot Five. Subject vehicle has turned right right right and is proceeding west on Great George Street. Subject vehicle now indicating offside. Over to you, Delta Seven.’

‘Delta Seven confirms the eyeball. Subject vehicle entering Lillybank Gardens, which is a one-way crescent. He’s looking to park.’

‘Yes yes.’

As Jim had explained, you need a story when you’re going around knocking on strangers’ doors, asking after people who don’t want to be found. Most people will just tell you – truthfully – that they don’t know who you’re talking about, but occasionally they’ll want to know why you’re asking, because they are the subject, or because they know the subject personally. You need to keep it simple, avoid extraneous detail and extrapolation. It was much the same principle as something she’d been taught at drama school, regarding acting on film or television: never do anything you can’t repeat precisely for ten more takes.

Jim had fed her a solid, time-proven script that he assured her would serve her for most occasions. She was looking for someone who had served in the navy alongside her father. The old man had retired a few months back and was trying to organise a reunion among the old shipmates with whom he had lost touch. When she eyeballed the subject and he confirmed his name, her out was that she had the wrong Peter Harper, this one being evidently too young. Sorry to trouble you, then out the door with the establish committed to the hidden video camera’s electronic memory.